Kherbouche Issam, MacRae Danielle, Geronimi Jourdain Théo, Lagugné-Labarthet François, Lamouri Azedine, Chevillot Biraud Alexandre, Mangeney Claire, Félidj Nordin
Université de Paris, ITODYS, CNRS, UMR 7086, 15 rue J-A de Baïf, F-75013 Paris, France.
Department of Chemistry, University of Western Ontario, 1151 Richmond St, London, Ontario N6A 5B7, Canada.
Nanoscale. 2021 Jul 1;13(25):11051-11057. doi: 10.1039/d1nr02181h.
Plasmonic excitation of metallic nanoparticles can trigger chemical reactions at the nanoscale. Such optical effects can also be employed to selectively and locally graft photopolymer layers at the nanostructure surface, and, when combined with a surface functionalization agent, new pathways can be explored to modify the surface of a plasmonic nanoparticle. Among these approaches, diazonium salt chemistry is seen as an attractive strategy due to the high photoinduced reactivity of these salts. In this work, we demonstrate that it is possible to trigger the site-selective grafting of aryl films derived from diazonium salts on distinct nano-localized area of single gold nanotriangles, by taking advantage of their multipolar localized surface plasmon modes. It is shown the aryl film will preferentially graft in areas where the electric field enhancement is maximum, independently of the considered excited surface plasmon mode. These experimental findings are in very good qualitative agreement with the calculations of the local electric field, using the finite-difference time-domain (FDTD) method. We believe that this plasmonic-based approach will not only pave a new way for the spatially controlled surface functionalization of plasmonic nanoparticles, but also provide a general strategy to attach distinct molecules to hot spot regions on a single nanoparticle, opening promising prospects in sensing and multiplexing, and optically nano-scale patterning of functional groups.
金属纳米颗粒的等离子体激发可以在纳米尺度上引发化学反应。这种光学效应还可用于在纳米结构表面选择性地局部接枝光聚合物层，并且，当与表面功能化剂结合时，可以探索新的途径来修饰等离子体纳米颗粒的表面。在这些方法中，重氮盐化学因其高的光致反应活性而被视为一种有吸引力的策略。在这项工作中，我们证明了利用单金纳米三角形不同纳米局部区域的多极局域表面等离子体模式，可以触发源自重氮盐的芳基膜在这些区域进行位点选择性接枝。结果表明，芳基膜将优先接枝在电场增强最大的区域，而与所考虑的激发表面等离子体模式无关。这些实验结果与使用时域有限差分（FDTD）方法进行的局部电场计算在定性上非常吻合。我们相信，这种基于等离子体的方法不仅将为等离子体纳米颗粒的空间控制表面功能化开辟一条新途径，而且还将提供一种将不同分子连接到单个纳米颗粒热点区域的通用策略，为传感和复用以及功能基团的光学纳米尺度图案化开辟广阔前景。
